Download Cells Use `Cellular` Phones

Cells Use ‘Cellular’ Phones!
Sivapriya Pavuluri
In multicellular organisms, cells often do not live in isolation. They stick to other cells or to the noncellular components of their environment. Protein molecules on the cell surface make cells sticky. One
of the most important groups of proteins that make cells sticky is integrin. An integrin is an integral
membrane protein and is made up of two subunits, the  subunit and the  subunit. There are 24 types
of integrins composed of one of 18  subunits and one of 8  subunits. Two main functions of integrins
are attachment of cells together and transmission of signals from the extracellular matrix to the cell.
Since integrins are useful for cell adhesion, growth, proliferation and differentiation, there might be a
chance for cancer promoting factors to use integrins in order to avoid apoptosis and invade different
parts of organs. Hence, it is useful to know how integrins work together with several growth factor
receptors in a coordinated manner and different signaling mechanisms etc.
During my project, I was able to perform a comparative analysis of the signals triggered by the 1subunit of integrin in 1A and 1B cells. I also cloned genes giving rise to smaller fragments of
integrins f (with several combinations like ) and put all those genes into
mouse cells. The idea behind iusing fragments rather than the whole integrins is to find the signaling
patterns resulting from combination of different types of integrins.
Every cell has to send information within its environment as well as outside. There are several proteins
involved in carrying different messages like cell survival, cell death, cell division etc from cell to cell
and with in cell to different molecules. Within the cell, integrins play a major role particularly in the
process of cell division and cell adhesion. They send messages to the nucleus to perform these
functions with the help of mediators called signaling proteins. There are different kinds of signaling
proteins, one of which is called Mitogen-activated protein kinases. They are helpful in sending
messages from integrins to the nucleus. In one of my experiment I was able to compare 1A and 1B
cells and differentiate the signaling patterns of mitogen-activated protein kinases.
Integrins are very important for the cell to adhere. Normal cells can adhere and cancer cells cannot
adhere. Since integrins are major proteins responsible for adhesion, topics such as mechanism of cell
signaling over the membrane by integrins, the cross talk between integrins and growth factor receptors
through several signaling molecules needed to be found in a detailed manner. Knowledge on such
topics will reveal how tumors can escape anchorage dependency growth and invade into several parts
of the body.
Degree project in Biology
Examensarbete i biologi, 20 p, HT 2005
Biology Education Centre and Department of Medical Biochemistry and Microbiology,
Uppsala University
Supervisor: Staffan Johansson